stl第一部分: string, vector, deque, stack

day9/stl_vector_demo/d10.cpp

@@ -0,0 +1,45 @@
+
+// vector 的删除操作
+#include <bits/stdc++.h>
+
+using namespace std;
+
+template <typename T>
+void print(vector<T> &v)
+{
+    typename vector<T>::iterator it = v.begin();
+    while (it != v.end())
+    {
+        cout << *it << " ";
+        it++;
+    }
+    cout << endl;
+}
+
+int main()
+{
+    int arr1[5] = {1, 2, 3, 4, 5};
+    vector<int> v1(arr1, arr1 + 5);
+    print(v1);
+
+    vector<int>::iterator it = v1.begin();
+    v1.insert(it, 1, 10); // 在 it 位置插入 1 个 10
+    print(v1);
+
+    it = v1.begin(); // 重新获取迭代器，因为之前的迭代器已经失效（插入后迭代器首地址变了）
+    v1.erase(it);    // 删除 it 位置的元素
+    print(v1);
+
+    it = v1.begin();
+    v1.erase(it, it + 2); // 删除 [it, it+2) 位置的元素
+    print(v1);
+
+    // 清空
+    v1.clear();
+    v1.empty(); // 判断是否为空
+    cout << "清空后：" << endl;
+    print(v1);
+    cout << "size: " << v1.size() << " capacity: " << v1.capacity() << endl; // size: 0 capacity: 8
+
+    return 0;
+}

day9/stl_vector_demo/d11.cpp

@@ -0,0 +1,35 @@
+
+// vector 的删除操作
+#include <bits/stdc++.h>
+
+using namespace std;
+
+template <typename T>
+void print(vector<T> &v)
+{
+    typename vector<T>::iterator it = v.begin();
+    while (it != v.end())
+    {
+        cout << *it << " ";
+        it++;
+    }
+    cout << endl;
+}
+
+int main()
+{
+    int arr1[5] = {1, 2, 3, 4, 5};
+    vector<int> v1(arr1, arr1 + 5);
+    print(v1);
+
+    vector<int>::iterator it = v1.begin();
+    v1.insert(it, 1, 10); // 在 it 位置插入 1 个 10
+    print(v1);
+
+    v1.resize(0);             // 缩小
+    vector<int>(v1).swap(v1); // 重新分配内存
+    print(v1);
+    cout << "size: " << v1.size() << " capacity: " << v1.capacity() << endl; // size: 2 capacity: 8
+
+    return 0;
+}

day9/stl_vector_demo/d3.cpp

@@ -0,0 +1,28 @@
+// vector 的使用
+
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int main()
+{
+    vector<int> v1;
+    // int mSize = v1.size();         // 获取容器中元素的个数
+    int mCapacity = v1.capacity(); // 获取容器的容量
+    int cnt = 0;                   // 扩容次数
+    cout << "初始容量: " << mCapacity << endl;
+    for (int i = 0; i < 1000; i++)
+    {
+        v1.push_back(i); // 向容器中添加元素
+        // cout << "size = " << v1.size() << " capacity = " << v1.capacity() << endl;
+        if (mCapacity != v1.capacity())
+        {
+
+            mCapacity = v1.capacity();
+            cout << "第" << ++cnt << "次扩容, "
+                 << "当前容量为: " << v1.capacity() << endl;
+        }
+    }
+
+    return 0;
+}

day9/stl_vector_demo/d4.cpp

@@ -0,0 +1,23 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int main()
+{
+    int arr[] = {1, 2, 3, 4, 5, 9}; // 静态数组
+    // vector<int> v1(arr, arr + 5);          // 动态数组，通过静态数组初始化
+    // vector<int> v1(arr, arr + sizeof(arr) / sizeof(arr[0])); // 动态数组，通过静态数组初始化
+
+    // 使用 assign 方法初始化
+    vector<int> v1;
+    v1.assign(arr, arr + sizeof(arr) / sizeof(arr[0]));
+
+    vector<int>::iterator it = v1.begin(); // 迭代器
+    while (it != v1.end())
+    {
+        cout << *it << " ";
+        it++;
+    }
+
+    return 0;
+}

day9/stl_vector_demo/d5.cpp

@@ -0,0 +1,28 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+template <typename T>
+void print(vector<T> &v)
+{
+    typename vector<T>::iterator it = v.begin();
+    while (it != v.end())
+    {
+        cout << *it << " ";
+        it++;
+    }
+    cout << endl;
+}
+
+int main()
+{
+    int arr1[5] = {1, 2, 3, 4, 5};
+    vector<double> v1(arr1, arr1 + 5);
+    vector<double> v2(5, 1.2f);
+    v1.swap(v2);
+
+    print(v1);
+    print(v2);
+
+    return 0;
+}

day9/stl_vector_demo/d6.cpp

@@ -0,0 +1,20 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int main()
+{
+    int arr1[5] = {1, 2, 3, 4, 5};
+    vector<double> v1(arr1, arr1 + 5);
+    cout << "size: " << v1.size() << endl;
+    cout << "capacity: " << v1.capacity() << endl;
+    cout << "first addr: " << &v1[0] << endl;
+
+    v1.resize(20); // 重新指定容器的长度
+    cout << "size: " << v1.size() << endl;
+    cout << "capacity: " << v1.capacity() << endl;
+    // 调整前后首地址会发生变化
+    cout << "first addr: " << &v1[0] << endl;
+
+    return 0;
+}

day9/stl_vector_demo/d7.cpp

@@ -0,0 +1,36 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+template <typename T>
+void print(vector<T> &v)
+{
+    typename vector<T>::iterator it = v.begin();
+    while (it != v.end())
+    {
+        cout << *it << " ";
+        it++;
+    }
+    cout << endl;
+}
+
+int main()
+{
+    int arr1[5] = {1, 2, 3, 4, 5};
+    vector<double> v1(arr1, arr1 + 5);
+
+    v1.resize(10, 9); // 重新指定容器的长度,并用9填充
+    print(v1);
+
+    vector<int> v2;
+    v2.reserve(3); // 预留足够的空间避免频繁扩容导致的首地址变化
+    // v2.resize(2); // resize 也可以预留空间，但是不会填充
+    v2.push_back(1);
+    cout << "first addr: " << &v2[0] << endl;
+    v2.push_back(2);
+    cout << "first addr: " << &v2[0] << endl;
+    v2.push_back(3);
+    cout << "first addr: " << &v2[0] << endl;
+
+    return 0;
+}

day9/stl_vector_demo/d8.cpp

@@ -0,0 +1,30 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+template <typename T>
+void print(vector<T> &v)
+{
+    typename vector<T>::iterator it = v.begin();
+    while (it != v.end())
+    {
+        cout << *it << " ";
+        it++;
+    }
+    cout << endl;
+}
+
+int main()
+{
+    int arr1[5] = {1, 2, 3, 4, 5};
+    vector<double> v1(arr1, arr1 + 5);
+
+    print(v1);
+
+    cout << "first element is: " << v1.front() << endl;
+    cout << "first element addr is: " << &v1.front() << endl; // 与 day9/d7.cpp 中的 first addr 不同
+    cout << "last element is: " << v1.back() << endl;
+    cout << "last element addr is: " << &v1.back() << endl; // 与 day9/d7.cpp 中的 first addr 不同
+
+    return 0;
+}

day9/stl_vector_demo/d9.cpp

@@ -0,0 +1,34 @@
+
+// vector 的插入操作
+#include <bits/stdc++.h>
+
+using namespace std;
+
+template <typename T>
+void print(vector<T> &v)
+{
+    typename vector<T>::iterator it = v.begin();
+    while (it != v.end())
+    {
+        cout << *it << " ";
+        it++;
+    }
+    cout << endl;
+}
+
+int main()
+{
+    int arr1[5] = {1, 2, 3, 4, 5};
+    vector<int> v1(arr1, arr1 + 5);
+    print(v1);
+
+    vector<int>::iterator it = v1.begin();
+    v1.insert(it, 1, 10); // 在 it 位置插入 1 个 10
+    print(v1);
+
+    vector<int>::iterator it2 = v1.begin();
+    v1.insert(it2, 2, 9); // 在 it 位置插入 2 个 9，之前的元素会向后移动
+    print(v1);
+
+    return 0;
+}